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Wednesday, February 29, 2012

Ism-itis!

People adhering to a particular faith, say X, are often called Xists or those who believe in Xism. Sometimes this is just a descriptor, but often it's used as a criticism, or worse. That's what happens when pole-headed right-wingers call President Obama a 'socialist' (something the pole-heads apparently know nothing about).

Sistine Chapel; Wikimedia Commons

This kind of ism/ist description applies in cultural combat but also in science. Thus people can be reductionist, frequentist, or falsificationist and so on, in the words of their detractors -- so these aren't compliments. People actually would not use the word about themselves if they feel that others use the term in a derogatory way.

Creationists (and they really are ists in the sense of holding tightly to a specific ideology or creed!) often denigrate people who understand the real world as 'evolutionists',as it is not clear exactly what these terms mean, which can be important. It is a castigating characterization when used by creationists, and it may imply that one is an ideolog about, rather than an explorer of, the subject of evolution.

We often refer critically on MT, to evolutionary or Darwinian or genetic 'determinists' or 'determinism.' However, our meaning is important to understand. At a seminar in our department a couple of years ago, when we questioned the nature of genetic determinism being invoked in some darwinian adaptive Just-So story-telling, someone stated that he was a determinist--"and isn't everyone?" Well, in science the answer is clearly yes, and no.

Here's where language gets in the way. If determinism means that Nature is causal and that every effect must have some cause, then most scientists would plead guilty to the charge. To invoke effects without cause is to be mystic, and certainly that has nothing to do with science. That doesn't mean that we have identified or understand the causation of effects under discussion, and there is where the legitimate issues lie.

Darwin, Museum of Natural
History, London;
Wikimedia Commons

Things are less transparent when it comes to 'selectionism'. If one makes the Darwinian assumption that whatever is here had to have got here by adaptive natural selection, then it is perfectly legitimate not to be a selectionist. Much in evolutionary reconstruction is of this type, and it often includes behavioral evolution or even morphology, where traits themselves can be hard even to define. If the trait must (by assumption) be the result of specific adaptive natural selection, then our task is to identify that selection. But we can always find some such reason, since the function today can be equated to having been the advantageous function in the past. This is entirely circular, and it's not science!

This doesn't mean that eyes or birds' wings or hominid locomotory apparatus got here 'by chance', as creationists still falsely often suggest, but it can mean that some functional elements ended up in our genomes by chance, if their initial harmfulness or helpfulness was slight compared to the populations they were in (in genetic terms, they got into the genome by 'drift'). Duplicate genes that have no harmful effect but provide redundancy that can subsequently be used for new function constitute one of many examples.

Selection must build on what's there, however it got there. Such chance-installed elements don't suddenly produce wings out of reptilian forelimbs, because complex traits involve too many changes. But the elements themselves need not have got here by selection, since most will have slight effect. Likewise, truly harmful things are eliminated by not being viable, and that is a form of selection, but not Darwinian or adaptive selection, since the defunct forms weren't really competing with anybody or anything. They just didn't work.

The bottom line here is that determinism depends on the degree to which (1) truly probabilistic cause exists, and/or (2) one believes that a specific cause under consideration perfectly predicts a specific outcome, and/or (3) the cause acts alone but only has predictive power if very accurately measured, and we can't get such quality measures. If a causal effect is truly probabilistic, it does not in the usual sense 'determine' the outcome. And if the cause is but one of many contributors, and hence has weak predictive power, or does so if inaccurately measurable, then arguing for 'determinism' stretches the truth and merits criticism. It doesn't mean there is no cause, but in these instances we cannot reliably or accurately predict the outcome from observing the cause.

Likewise for adaptive selectionism or 'Darwinism'. If selection is weak, sporadic, erratic, or distributed over many different contributing factors, or if there is no selection but only drift, or if there is selection but we have no serious way to argue what its mechanism was, then the adaptationist argument stretches the truth and merits criticism. Knowing the genes involved in a trait doesn't predict their change from on generation to the next and, indeed, different genotypes can generate the same phenotype, so that we cannot infer the cause from the result. Again, this doesn't mean there is no cause, but it does mean that selectionism is over-stated.

What we argue when criticizing what we think are excessive claims of genetic determinism or selectionism is that the assertion being made does not bear scrutiny in these above senses. We're not arguing for mystical causation or effects that are not 'determined' by physical causes. We may be arguing that we have little idea or way of knowing what the cause(s) was or were, or that the assumption of a kind of causation can be made self-fulfilling rather than really scientifically testable. It often seems to be true that based on methods and criteria we use today, some of these causal situations simply cannot in principle be worked out beyond some very imperfect level of precision. Things too probabilistic, or too weak to be understood from the kinds of samples we can actually collect, are simply not accurately predictable from observing putative causes, and that also means we have inadequate ways of even identifying the causes.

We do seem to live in an orderly causal world. There are 'laws' of Nature, even if the word is a human one that doesn't imply a law-giver. Whether causation can be truly probabilistic, and whether there may be causal aspects whose very existence humans have not learned to detect or characterize, we have no idea. Nor does anybody else. There are wild theories of multiple universes to get around pure probabilistic causes, and things like dark matter and energy to get around some of what we observe in ordinary matter. Who knows what else someone may some day discover. Given this, we believe that more circumspection is in order about causal claims in the life sciences. In part this is because science has practical implications for society, can be used towards evil or harmful ends (even if unintentionally), and costs resources that could be used for other things, if we had a less lobbying-based or ideological social environment in terms of making such decisions.

To argue that someone is a 'determinist' is not to label them with a slur as if they should instead by a mystic or crystal ball reader. It is to argue that assertions should be tempered, and we should take more seriously the things that are clearly inadequately known but could be quite fundamental. To be a 'Darwinian' or 'adaptationist' can mean not just that one recognizes the clear truth of evolution as a fact, and that survival requires success by definition, but can refer to someone who goes beyond that, to and assumes what is to be shown, and that certainly is not good science. One wants to have an interpretive framework, without which science would be difficult if not impossible, but the framework needs to be tested rather than assumed.

Assuming a framework--being an 'ist'--may be good for hustling attention or grants, but not for a more serious--if avowedly less complete--understanding of things that we now have or than the ists of this world would lead you to believe.

4 comments:

"There are wild theories of multiple universes to get around pure probabilistic causes, and things like dark matter and energy to get around some of what we observe in ordinary matter."

As you know, I am not a scientist. But for over 30 years I've followed various matters in cosmology and quantum physics. I can't argue against "pure probabilistic causes" in general, but I can't help remembering that, if I am not mistaken, Schrödinger, in his famous "cat" thought experiment, was arguing against, not for, the Copenhagen interpretation, pointing out the utter absurdity of a cat that is "a superposition of dead and alive" until the box is opened. Is such a construct really less "wild" than a universe that splits and runs on two threads (maybe re-merging, maybe not)?

As I said, I'm not qualified to judge on that. But 40-50 years ago, a many-worlds interpretation would literally get you laughed out of a quantum physics seminar, and today at least some physicists seem to be giving it... or some variant of it... serious consideration again.

I haven't been able to get my head around the multiverse idea (a good popular-science book, but now some years ago, was by David Deutsch--I forget the title--and there are Wiki and other sources on the idea.

I also can't grasp the nuances of the Copenhagen vs other interpretations of quantum physics, as to whether things are really probabilistic or just unavoidably look that way.

But I think that the patterning of light, and the duality of particles (in instant communication with each other, though separate) are real phenomena.

Maybe humans just haven't yet got a right intuition or methodology to understand these things, or maybe ideas we can't grasp because they seem too strange is an artifact of what, based on daily life, we just happen to think are strange.

I reserve the term "determinism" for non-theists and theists who hold to hard determinism or soft determinism (compatibilism), which philosophy refers to as "causal determinism."

Augustine and many Calvinist are examples of theist soft determinist. Online, I met several theists who are hard determinists, but I am unsure if any theist scholars are hard determinists.

As far as non-theists are concerned, many who hold to an eternalist/block theories of time are causal determinists and reject the reality of probability.

I think that the true meaning of the term "genetic determinism" does not reject that environmental factors affect morphology and behavior. And I think many confuse the meaning of genetic determinism with philosophical concepts of determinism.

No serious geneticist would deny I don't know what fraction would say they accept inherently probabilistic effects (they'd say that we just don't know enough to do better;see our earlier series on probabilism).

But look at what people do rather than what they say they do. When they hype personalized genomic medicine, the tone of their statements leads on to believe that your life can be predicted from your genotype. Even if they put in some caveats about probabities rather than certainties, the impression they know that they're giving (esp. to funders?) is that they have the crystal ball to see into your very soul.

I can't comment on your theism issues because I'm essentially totally ignorant about them. I did think that Calviinists were true determinists in that you were either chosen, or not chosen, when you were conceived and nothing could change that. You looked at your life as evidence for the underlying pre-determined state.

Anyway, if we were to accept only weak or very weak predictive power of genotypes and stop hinting that it was greater, we'd be being more honest.

And what are the predicted probabilities based on? On the fraction of people with a given genotype who got a given disease, say. But even when acknowledging environmental contributions, the genetic 'determinists' falsely attribute rigor to the risk probabilities, because risk estimates are based on past exposure of present adults, and we cannot know what the exposures are of those born today whose genomes we want to use as our crystal balls.

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